Collaborate Disseminate
If you’ve ever been laying out a network I2C devices inside a project box or throughout your robot’s body, you’ll probably know that I2C is not without its pitfalls. But …read more Continue reading Extenders And Translators For Your I2C Toolkit
Using hardware I2C on an ESP32? Do you need to connect multiple I2C devices with the same address? Normally, you wouldn’t be able to do that without extra parts, but …read more Continue reading Avoid I2C Address Conflicts On ESP32 By Pin Muxing
I2C is a wonderful interface. With four wires and only two GPIOs, you can connect a whole lot of sensors and devices – in parallel, at that! You will see …read more Continue reading The Connector Zoo: I2C Ecosystems
Many readers will be familiar with interfacing I2C peripherals. A serial line joins a string of individual I2C devices, and each of the devices has its own address on that line. In most cases when connecting a single device or multiple different ones there is no problem in ensuring that they have different addresses.
What happens though when multiple identical devices share an I2C bus? This was the problem facing [Sam Evans] at Mindtribe, and his solution is both elegant and simple. The temperature sensors he was using across multiple identical boards have three pins upon which can be set …read more
Continue reading Automatic I2C Address Allocation For Daisy-Chained Sensors
The LTC4316 is something special. It’s an I²C address translator that changes the address of a device that would otherwise conflict with another on the same I²C bus. Not a hack? Not so fast. Exactly how this chip does this trick is clever enough that I couldn’t resist giving it the post it rightfully deserves.
What’s so special? This chip translates the address on-the-fly, making it transparent to the I²C protocol. Up until this point, our best bet for resolving address collisions was to put the clashing chip on a separate I²C bus that could be selectively enabled …read more
If you’re reading these pages, odds are good that you’ve worked with I²C devices before. You might even be the proud owner of a couple dozen sensors pre-loaded on breakout boards, ready for breadboarding with their pins exposed. With vendors like Sparkfun and Adafruit popping I²C devices onto cute breakout boards, it’s tempting to finish off a project with the same hookup wires we started it with. It’s also easy to start thinking we could even make those wires longer — long enough to wire down my forearm, my robot chassis, or some other container for remote sensing. (Guilty!) In …read more
Continue reading Taking the Leap Off Board: An Introduction to I2C Over Long Wires
You will probably be familiar with I²C, a serial bus typically used for not-very-fast communication with microcontroller peripherals. It’s likely though that unless you are an I²C wizard you won’t be intimately familiar with the intricacies of its operation, and each new device will bring a lengthy spell of studying data sheets and head-scratching.
If the previous paragraph describes you, read on. [Clint Stevenson] wrote a library for interfacing I²C EEPROMs to Arduino platforms, and when a user found a bug when using it on an ATtiny85, he wrote up his solution. The resulting piece is a clear explanation …read more
[Igor] wished to upgrade his newly acquired radio — a Baofeng UV-82 — with a larger memory for storing additional scanning channels, and came up with a very elegant solution: Replacing it’s EEPROM with a larger one and injecting the additional memory address bits into the I2C data line.
The cheap handheld radio comes with an 8192 bytes large 24c64 EEPROM, which allows it to store 128 channels along with a few other persistent settings. The radio’s firmware sends two-byte memory addresses over the I2C bus when accessing the 24c64, but since the 24c64’s largest address is B00011111 11111111, these addresses always roll in with …read more
Continue reading I2C Bit Injection Adds Memory Banks To Everything
